mmc: core: Convert to mmc_poll_for_busy() for erase/trim/discard

Rather than open coding the polling loop in mmc_do_erase(), let's convert
to use mmc_poll_for_busy().

To allow a slightly different error parsing during polling, compared to the
__mmc_switch() case, a new in-parameter to mmc_poll_for_busy() is needed,
but other than that the conversion is straight forward.

Besides addressing the open coding issue, moving to mmc_poll_for_busy() for
erase/trim/discard improves the behaviour according to below.

- Adds support for polling via the optional ->card_busy() host ops.
- Returns zero to indicate success when the final polling attempt finds the
  card non-busy, even if the timeout expired.
- Exits the polling loop when state moves to R1_STATE_TRAN, rather than
  when leaving R1_STATE_PRG.
- Decreases the starting range for throttling to 32-64us.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Tested-by: Ludovic Barre <ludovic.barre@st.com>
Reviewed-by: Ludovic Barre <ludovic.barre@st.com>
Link: https://lore.kernel.org/r/20200204085449.32585-9-ulf.hansson@linaro.org

1 files changed, 2 insertions, 34 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index a971c4bcc442..3f7a31456eb4 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1658,8 +1658,6 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
 	struct mmc_command cmd = {};
 	unsigned int qty = 0, busy_timeout = 0;
 	bool use_r1b_resp = false;
-	unsigned long timeout;
-	int loop_udelay=64, udelay_max=32768;
 	int err;
 
 	mmc_retune_hold(card->host);
@@ -1763,38 +1761,8 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
 	if ((card->host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp)
 		goto out;
 
-	timeout = jiffies + msecs_to_jiffies(busy_timeout);
-	do {
-		memset(&cmd, 0, sizeof(struct mmc_command));
-		cmd.opcode = MMC_SEND_STATUS;
-		cmd.arg = card->rca << 16;
-		cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
-		/* Do not retry else we can't see errors */
-		err = mmc_wait_for_cmd(card->host, &cmd, 0);
-		if (err || R1_STATUS(cmd.resp[0])) {
-			pr_err("error %d requesting status %#x\n",
-				err, cmd.resp[0]);
-			err = -EIO;
-			goto out;
-		}
-
-		/* Timeout if the device never becomes ready for data and
-		 * never leaves the program state.
-		 */
-		if (time_after(jiffies, timeout)) {
-			pr_err("%s: Card stuck in programming state! %s\n",
-				mmc_hostname(card->host), __func__);
-			err =  -EIO;
-			goto out;
-		}
-		if ((cmd.resp[0] & R1_READY_FOR_DATA) &&
-		    R1_CURRENT_STATE(cmd.resp[0]) != R1_STATE_PRG)
-			break;
-
-		usleep_range(loop_udelay, loop_udelay*2);
-		if (loop_udelay < udelay_max)
-			loop_udelay *= 2;
-	} while (1);
+	/* Let's poll to find out when the erase operation completes. */
+	err = mmc_poll_for_busy(card, busy_timeout, MMC_BUSY_ERASE);
 
 out:
 	mmc_retune_release(card->host);